class OutOfMaxGenerater(Exception):
    pass

class InvaildDispatcher(Exception):
    pass

class RequirementCrashed(Exception):
    pass

class DisabledNamespace(Exception):
    pass

class ExistedNamespace(Exception):
    pass

class UnexistedNamespace(Exception):
    pass

class RegisteredEventListener(Exception):
    pass

class InvaildEventName(Exception):
    pass

class InvaildContextTarget(Exception):
    pass

class PropagationCancelled(Exception):
    pass